A NUMERICAL STUDY OF THE EFFECT OF TAIWAN ISLAND TERRAIN ON TYPHOON HAITANG (0505) TRACK

The track of Typhoon Haitang(0505),which passed through the Taiwan Island and landed again,was successfully simulated by using the non-hydrostatic mesoscale atmospheric model MM5.Its structure was analyzed on the landing stage,and it could be found that there existed good relationships between the typhoon abnormal moving track and its asymmetry structure.The effect of terrain of Taiwan Island on the typhoon Haitang,which made it rotate before landing and present a V type abnormal moving track in Taiwan straits,was also simulated.Further analysis showed that the terrain of Taiwan Island not only directly affected the typhoon moving track,but also changed the typhoon track by affecting its asymmetric structure.Therefore,the typhoon asymmetric structure and the effect of terrain of Taiwan Island together resulted in the abnormal rotating track.The terrain of Taiwan Island tends to increase the SW-NE asymmetric structure of the typhoon and has different effect on SE-NW asymmetric structure during the landfall process of typhoon Haitang before entering and moving out of the Taiwan straits.